The present invention relates to a headlamp for motor vehicles, which can generate selectively a full light beam and a dipped/fog light beam.
The headlamps which are fitted at present onto motor vehicles perform the full- and dipped-beam functions by means of a two-filament halogen lamp and substantially bifocal optics, or by means of two single-filament lamps, and separate optics. In the first case, the headlamp comprises a bifocal reflector, along the optical axis of which, and more specifically at the focal point of which, there are disposed the two filaments of the lamp, which can be actuated alternately; an intermediate screen which is disposed facing one of the two filaments, and can intercept part of the light emitted by this filament, in order to obtain as output from the headlamp a dipped light beam which is provided with the corresponding cut-off (i.e. with the corresponding light/dark demarcation line), whereas the light emitted by the second filament is used entirely for generation of the full light. In the second case, two separate reflectors are provided, each for a single filament lamp, and are designed in order to obtain respectively a full light beam and a dipped light beam.
Each of the two above-described solutions requires a compromise between simplicity, economic viability and size.
The object of the present invention is to provide a headlamp which can be fitted to motor vehicles, which is at the same time simple, economical, and has a reduced size.
On the basis of the invention, there is thus provided a headlamp for motor vehicles, which can generate-selectively a full light beam and a dipped/fog light beam, comprising a single light source, intermediate screens, which are at least partially mobile, and can intercept part of a light flow emitted by the light source, and movement means, which can displace the said mobile intermediate screens selectively, between at least two different positions: in the first of these positions, the intermediate screens can intercept part of the light flow, whereas in the second position, they do not intercept the flow.
In particular, the intermediate screens comprise a fixed intermediate screen, which can define a light/dark demarcation line of the dipped/fog beam, and a mobile intermediate screen; the said intermediate screens are held together by means of a hinge which can permit rotation of the mobile intermediate screen. When the intermediate screens are in the first operating position, in order to permit passage of a light beam obtained from the lower reflecting part, the mobile intermediate screen is disposed substantially parallel to the optical axis, and substantially at right angles to the fixed intermediate screen, and when the intermediate screens are in the second operating position, in order to intercept a light beam from the lower reflecting part, the mobile intermediate screen is disposed substantially at right angles to the optical axis, and substantially aligned with the fixed intermediate screen.
This therefore provides a headlamp which can perform the full beam and dipped/fog beam functions by means of a single lamp with a single filament, and bifocal optics. The solutions proposed are simple and economical, and provide the structure with a minimum size, and which can be adapted to different models of motor vehicles.